1. Field of the Invention
The present invention relates to a mounting for being interposed between an engine and a vehicle frame, and more particularly to the structure of a fluid-sealed engine mounting having therein a chamber in which a fluid is sealed.
2. Description of the Prior Art
One known type of fluid-seal engine mounting comprises a connector adapted to be connected to an engine, a base adapted to be connected to a vehicle frame, and an elastic member joined between the connector and the base and elastically deformable as vibrations are transmitted therethrough. The mounting has a chamber defined by the connector, base, and elastic member, with a fluid sealed in the chamber. The elastic member is composed of two upper and lower members with a partition interposed therebetween and dividing the chamber into upper and lower chambers. The partition has an orifice through which the upper and lower chambers are kept in communication with each other. Such an engine mounting is disclosed in Japanese Laid-Open Patent Publication No. 58-25843, for example. The prior engine mounting has improved dynamic characteristics achieved by the dampening of vibrations due to the movable orifice at the time the partition resonates and the dampening of vibrations due to the upper and lower elastic members. The known engine mounting has a shortcoming in that since the upper and lower chambers are of equal volumes, the vibration dampening by the orifice is accomplished only when the partition resonates. Another drawback is that because the base is in the form of a single flat plate, if a diaphragm is attached to the base, then it is difficult to connect the base to a fixed member such as the vehicle frame.
Therefore, it is an object of the present invention to provide a fluid-sealed engine mounting including a partition having an orifice which is also effective in dampening vibrations when the partition does not resonate.
Another object of the present invention is to provide a fluid-sealed engine mounting having a base that can easily be coupled to a fixed member even with a diaphragm attached to the base.
According to the present invention, there is provided a fluid-sealed engine mounting for mounting an engine on a vehicle frame, comprising a connector adapted to be connected to the engine, a base adapted to be connected to the vehicle frame, an elastic member joined between the connector and the base and elastically deformable in response to vibrations transmitted thereto, the connector, the base, and the elastic member jointly defining a fluid chamber in which a fluid is sealed, a partition dividing the fluid chamber into a first chamber adjacent to the connector and a second chamber adjacent to the base, the partition having an orifice through which the first and second chambers communicate with each other, and a diaphragm mounted on the connector or the base for varying the volume of one of said first and second chambers when vibrations are transmitted to the engine mounting.
The base comprises a tubular body having a radially outwardly projecting flange on one end thereof and a radially inwardly opening recess in an opposite end thereof. The diaphragm has a peripheral edge gripped in the radially inwardly opening recess in the base. The fluid-sealed engine mounting is connected by the flange to the vehicle frame.